Duplicating process and products



Nov. 9, 1965 M. SHARKEY 3,216,350

DUPLICATING PROCESS AND PRODUCTS Filed July 22, 1964 INVENTOR MelvinSharke y MQQHZM HT roe/v.5 Y5

3,216,350 DUPLICATING PRQCESS AND PRGDUCTS Melvin Sharkey, 1614 HerefordRoad, Hewlett, N.Y. Filed July 22, 1964, Ser. No. 384,305 12 (Zlaims.(Cl. fill-149.4)

The present invention relates to a novel dry hectograph duplicatingprocess and to the imaged master sheets for use in such process.

In the conventional spirit hectograph duplicating process, dye imagesare typed or drawn onto a master sheet and these images are duplicatedonto copy sheets which have been wetted with volatile dye solvent suchas ethanol, the solvent dissolving dye from the images onto the copysheet prior to its evaporation.

While the spirit process enjoys widespread commercial success, it has atleast one great disadvantage which prohibits its use for certainapplications such as for the production of copies of patterns used inthe garment industry. The spirits used in the spirit duplicating processare very volatile and combustible and therefore present a fire andexplosion hazard which prevents their use in areas where prohibited byfire laws.

A number of dry hectograph processes have been proposed in an effort toeliminate the necessity of using volatile spirits. Most of these methodsemploy non-volatile dye-solvent coatings on the copy sheets so that whenmaster images are pressed thereagainst, portions of the master imagesare transferred to the copy sheet coating and gradually dissolvedtherein. Such a process, such as taught by U.S. Patent No. 3,034,428,has the disadvantages that dissolution and development of the dye coloron the copy sheet is slow and uncontrollable since a mass of dye ispressure-transferred to the copy sheet and the copy sheet coatingcontinues to dissolve the dye into areas States Patent adjacent to theareas which actually support the dye images so that broadening andblurring of the images results.

However, equally objectionable is the fact that the specially-coatedcopy sheets are expensive and this expense, when added to the expense ofproviding conventional master paper which is also costly, makes theprocess prohibitive for a large-scale web-copy operation as is used inthe pattern-copying field.

A dry copy process has been proposed in U.S. Patent No. 2,501,495 whichemploys conventional copy paper. According to this process, dye imagesare typed upon the resinous coating on a master sheet and the images arethen pressed against a copy sheet while the master is cooled and thecop-y sheet is heated. This process is rather tedious due to thenecessity of closely controlling the temperature of a cooling roll and aheating roll in close proximity, but more importantly this process isnot a hectograph or dye-dissolving process but depends upon the masstransfer of portions of the master images to each copy sheet.Undissolved dyestulf is so easily smudged and has such a tremendousstaining power that the copies imaged by this process cannot be handledwithout blurring the images and staining the hands and clothing. Thismakes such copies useless in the pattern field where staining of thefabric being cut cannot be tolerated.

With these problems and disadvantages of the prior art in mind, it is anobject of the present invention to provide a novel dry hectographcopying process in which dye images can be dissolved onto conventionalcopy papers without the use of volatile spirits and without thenecessity and expense of using specially-coated copy sheets.

It is another object of this invention to provide imaged hectographmaster sheets which are dry-to-the-touch but which are activated bymeans of heat to provide sufii- 'ice cient non-volatile dye solvent todissolve the dyestulf in the master images so that it can be transferredin developed, dissolved form to a copy sheet under the elfects of evenslight pressure.

It is still another object of the invention to provide imaged hectographmaster sheets which can be used periodically for the production ofduplicate copies by means of heat alone and which revert to dry, stableform upon cooling after each use.

These and other objects and advantages are accomplished according tothis invention in a manner which will be clear to those skilled in theart in the light of the present disclosure including the drawing, inwhich:

FIGURE 1 is a diagrammatic cross-section, to an enlarged scale, of animaged hectograph master sheet according to the present invention.

FIG. 2 is a sectional view showing an arrangement of a master-carryingdrum, a master sheet heating system and a pressure roll included in anapparatus suitable for carrying out the process used herein forduplicating and transferring hectograph images from a master sheet tosuccessive copy sheets.

FIG. 3 is a sectional view of an arrangement of a continuous mastersheet and a continuous copy sheet, as used in the pattern making art.

The objects and advantages of the present invention are accomplished byproviding as a master sheet a paper foundation having thereon aheat-meltable coating comprising at least a major amount by weight ofone or more heat-meltable materials which, in their melted state, aresolvents for the dyestulf in the images placed upon the master sheetcoating. The imaged master sheet is dry and may be handled and storeduntil copies of the imaged subject matter are desired. At such time, asmany copies as desired may be produced on plain copy paper by merelyheating the master sheet to melt the coating thereon and bringing theheated master sheet into pressure contact with a succession of copysheets.

The mode of operation of the present master sheets is not completelyunderstood although it appears that the dissolving of the master imagesis brought about mainly by a spreading of the melted solvent coatingover the images when the master is placed in pressure contact with eachcopy sheet. This provides a fresh supply of dissolved dyestulf for eachcopy sheet and brings about a slow metering of the dyestuff from themaster sheet to the succession of copy sheets.

Referring to the drawing, FIG. 1 illustrates a master sheet 10 having apaper foundation 11 carrying a heatmeltable dye-solvent layer 12 anddye-containing images 13. The nature of the heat-meltable dye-solventlayer 12 forms a critical part of the present invention. This layer mustbe non-pressure-transferable and therefore is applied as a relativelythin layer most of which is present in the form of an impregnation ofthe paper foundation. Because of the differences in the absorbency ofpapers of different types, it is impossible to place a limitation on theamount of dye-solvent coating to be applied. However, it is clearlywithin the skill of the artisan to apply the dye-solvent compositions insuch amounts that the entire surface of the paper sheet is filled andsmoothed to produce a continuous coating which is not sufficiently thickto be pressure-transferable.

The dye-solvent coating compositions of this invention preferablyconsist of one or more solid materials which are dye solvents in theirmelted state and which melt at a temperature within the range of fromabout F. to about 250 F. and preferably within the range of from F. toabout F. Materials found suitable for this purpose include solid fattyalcohols such as cetyl, myristyl and stearyl alcohols; solid fatty acidssuch as stearic, palmitic, lauric and capric; solid esters of variousglycols and organic acids, and solid glycol ethers such aspolyethyleneand polypropylene-glycol ethers. It has also been foundpossible to use higher melting point solid dye solvents or lower meltingpoint solid or liquid dye solvents provided that they are used inadmixture with other solid dye solvents to provide a composition havinga melting point between 80 F. and 250 F.

The aforementioned dye solvents, either alone or in admixture with smallamounts of low melting point wax binder materials such as beeswax,mineral wax or the like, are coated onto a paper web to form a thin,smooth, continuous coating thereon. The coating must be substantiallynon-pressure-transferable and while it is difiicult to give a suitablerange of coating weights due to the differences in absorptivity ofdifferent paper stocks, in general the coating is applied in a weightranging between 2 and 7 pound per ream (25" x 38" x 500 sheets).

The prepared master web is used in web form for the production of largecopies such as garment patterns or may be reduced to sheet lengths. Themaster is imaged on the dye-solvent coating in conventional manner bysuperposing the master and a hectograph transfer sheet, the transferlayer being against the dye-solvent coating, and applying imagingpressure against the back of the master sheet to transfer mirror-reverseimages to the dye-solvent coating. The hectograph composition of thetransfer sheet must have a higher melting point than the dye-solventcoating.

The imaged master sheet may then be used .to form duplicate copies byplacing the imaged side of the master against any copy paper, applyingsufiicient pressure to insure overall contact, and applying heat such asby a heated pressure means such as a heated iron, a hot plate, a heateddrum or roller, or by infrared radiation or the like, whereby thedye-solvent coating becomes melted and penetrates, surrounds andenvelops the unmelted master images and dissolves the dyestuff thereinwhereby the dissolved dyestuff stains the copy sheet to form thereondissolved dye images corresponding to the master images.

If desired, the imaged master sheet may be heated before it is contactedwith the copy sheet, provided that contact is made while the dye-solventcoating is still in the melted state. Also in cases where it is desiredto use infrared radiation as the heating means, it is preferred that themaster paper he pigmented dark and/ or that the copy paper have a darkcoating on the back side so that it will absorb the infrared radiationand convert it to heat. The dye-solvent coating should not be pigmenteda dark color but rather should be clear or translucent or pigmented alight color such as white to correspond with the color of the copy sheetso as not to be noticeable if melted portions thereof transfer to thecopy sheet during the duplicating process.

Any suitable apparatus may be used for the present duplicating processprovided that it includes heating means to heat the master sheet between80 F. and 250 F. to melt the dye-solvent coating, and pressure means toforce the heated master into intimate surface contact with the copysheet.

The device illustrated by FIG. 2 comprises a heated drum 20 havingmounted thereon the imaged master sheet 10 and a pressure roller 30urged against the heated drum. Drum is internally heated by means ofelectrical heating means 21 to provide a temperature at the surface ofthe drum sufiiciently high to melt the coating on the master sheet. Ifdesired, external heating means such as infrared radiation lamp 22 maybe used as a supplement to or in place of the internal heating means 21.Copies are made by urging a copy sheet 15 between the drum and thepressure roller whereby the dissolved dyestuif in the master images 13stains the surface of the copy sheet to form duplicate images thereon.These duplicate images have an instant color since they consist ofdissolved dyestuff, and they are substantially nonsmearing andclean-to-the-touch since they are free of undissolved dyestuff or wax.

The embodiment illustrated by FIG. 3 of the drawing pertains tocontinuous web copying whereby a continuous imaged master sheet 10 fromsupply roll 41 and a continuous copy sheet 15 from supply roll 51 areurged into pressure contact between roller 25 and pressure roller 30 toeffect the duplicating step after which the master sheet is wound ontake-up roll 42 and the imaged copy sheet carrying dye images 14 iswound on take-up roll 52. The heating of the master sheet prior tocontact with the copy sheet is accomplished by infrared radiation lamps22 and, if desired, by internal heating means in roller 25.

It is a critical feature of the present invention that the hectographdyestuff images 13 on the master sheet must be non-meltable at thetemperature used to effect the present duplicating process since meltingof the master images would permit a melting-over or mass transfer to thecopy sheet so that the images formed thereon would contain undissolveddyestufl and wax binder material and would be easily smudged and verydirty-to-the-touch. In other Words, if the master images are melted atthe temperatures employed, then the transfer would consist of solidrather than dissolved dyestuif and the formed copy would itself beuseful as a master sheet.

Any conventional hectograph transfer sheet may be used to image thepresent master sheets provided that the hectograph composition has ahigher melting point than the temperature used to melt the dye-solventlayer in the duplicating operation. Most wax-base hectographcompositions melt above F. and are well suited for use according to thepresent invention. Lower melting wax-base compositions may be usedprovided that very low melting point dye-solvent coatings are used andthe temperature used in the duplicating operation is between the meltingpoint of the coating and the melting point of the images.

If desired, higher melting point solvent-applied hectograph compositionsbased upon film-forming binder materials such as cellulose plastics,vinyl resins and hydrophilic colloids may be used in place of hot meltwax compositions. Such compositions have a melting point Well in excessof 250 F.

In most cases it has been found preferable to use hectograph transfersheets on which the transfer layer has a low caliper or thickness in thearea of from 2 to 6 points (0.0002 to 0.0006 inch or 0.2 to 0.6 mil)since such thin layers deposit thin master images on the master sheet.Since the image dissolution on the master sheet appears to be the resultof the melted dye solvent spreading over the master images, then it ispreferred to maintain the dye-solvent coating and the height of themaster images on as equal a plane as possible. It has been found thatthin hectograph layers are preferred and that the height of imagesplaced with such thin layers is nearly on an equal plane With thesurface of the dyesolvent coating due to embossing and/or displacementof the dye-solvent coating in the impressed areas.

In cases where the melting of the dye-solvent coating is effected bymeans of infrared radiation lamps, the master images should consist of ahectograph composition which absorbs little, if any, of the radiation.Most conventional hectograph compositions and dyestuffs are suitable inthis regard.

It should be understood that melting of the coating on the master sheetmay be effected in any number of ways other than by applying heatdirectly to the master sheet. For instance the copy sheet may be heatedbefore or during its contact with the master whereby heat is transferredto the master to cause the melting of its coating. Also the process maybe carried out in a heated atmosphere such as an oven whereby the copysheet, master sheet and master images are heated to the same extent.

Variations and modifications may be made within the scope of the claimsand portions of the improvements may be used without others.

I claim:

1. The process of duplicating master images onto a succession of copysheets which comprises the steps of:

(a) forming a master sheet by applying to a paper foundation sheet athin solid coating which is substantially non-pressure-transferable andwhich comprises at least one solid solvent material which, in its meltedstate, is a solvent for a hectograph dyestutf,

(b) applying over said solid coating images which contain an undissolvedhectograph dyestutf which is soluble in the melted solvent material ofthe coating, said images having a melting temperature higher than themelting temperature of the said solid coating, and

(c) heating the imaged master sheet to a temperature sufiiciently highto melt the solid coating without melting the images, and

(d) pressing the heated master sheet against a succession of copy sheetswhereby the melted solvent material dissolves a portion of thehectograph dyestufi onto each copy sheet surface to stain each copysheet surface pressed thereagainst to form dissolved dyestuif images onthe copy sheets in areas correspond ing to the imaged areas of themaster sheet.

2. The process according to claim 1 in which the coating on the mastersheet has a melting point within the range of from about 80 F. to about250 F., the images thereon have a higher melting point, and sufiicientheat is applied to create a temperature of between about 80 F. and 250F. in the coating of the master sheet to melt the coating withoutmelting the images thereon.

3. The process according to claim 1 in which the solvent materialcomprises at least one material selected from the group consisting offatty acids, fatty alcohols, solid esters and solid ethers.

4. The process according to claim 1 in which the images which containundissolved dyestuff include a binder material selected from the groupconsisting of wax and film-forming binder materials.

5. The process of duplicating master images onto a succession of copysheets which comprises the steps of:

(a) forming a master sheet by applying to an infraredradiation-absorbing paper foundation sheet a thin solid coating whichhas a melting temperature in the range of 80 F. to 250 F., which issubstantially non-pressure-t-ransferable and which comprises at leastone solid solvent material which, in its melted state, is a solvent fora hectograph dyestuif,

(b) applying over said solid coating images which contain an undissolvedhectograph dyestulf which is soluble in the melted solvent material ofthe coating and which does not absorb infrared radiation, said imageshaving a melting temperature higher than the melting temperature of thesaid solid coating, and

(c) applying infrared radiation to heat the imaged master sheet to atemperature sufficiently high to melt the solid coating without meltingthe images, and

(d) pressing the heated master sheet against a succession of copy sheetswhereby the melted solvent material dissolves a portion of thehectograph dyestuff onto each copy sheet surface to stain each copysheet surface pressed thereagainst to form dissolved dyestuff images onthe copy sheets in areas corresponding to the imaged areas of the mastersheet.

6. The process of duplicating master images onto a succession of copysheets which comprises the steps of:

(a) forming a master sheet by applying to a paper foundation a thinsolid coating which has a melting temperature in the range of 90 F. to160 R, which is substantially non-pressure-transferable and whichcomprises at least one solid solvent material which, in

6 its melted state, is a solvent for a hectograph dyestufl",

(b) applying over said solid coating images which contain an undissolvedhectograph dyestutf which is soluble in the melted solvent material ofthe coating, said images having a melting temperature higher than themelting temperature of the said solid coating, and

(c) superposing the imaged master sheet with its images in surfacecontact with a succession of copy sheets, and

(d) applying a heated pressure means against the master sheet to pressthe master sheet into intimate surface contact with each copy sheet andmelt the coating on the master sheet without melting the images thereonwhereby the melted solvent material dissolves a portion of thehectograph dyestuff onto each copy sheet surface to stain each copysheet surface pressed thereagainst to form dissolved dyestutf images onthe copy sheets in areas corresponding to the imaged areas of the mastersheet.

7. The process of duplicating master images onto a succession of copysheets which comprises the steps of:

(a) forming a master sheet by applying to a paper foundation a solidcoating having a weight of between about 2 and 7 pounds per ream andhaving a melting temperature in the range of F. to 250 E, which issubstantially non-pressure-transferable and which comprises at least onesolid solvent material which, in its melted state, is a solvent for ahectograph dyestuff and which is selected from the group consisting offatty acids, fatty alcohols, solid esters and solid ethers,

(b) applying over said solid coating on the master sheet images whichcontain a hectograph dyestuff which is soluble in the melted solventmaterial of the coating, said images having a melting temperature higherthan the melting temperature of the said solid coating, and

(c) heating the imaged master sheet to a temperature sufiiciently highto melt the solid coating without melting the images, and

(d) pressing the heated master sheet against a succession of copy sheetswhereby the melted solvent material dissolves a portion of thehectograph dyestufi onto each copy sheet surface to stain each copysheet surface pressed thereagainst to form dissolved dyestutf images onthe copy sheets in areas corresponding to the imaged areas of the mastersheet.

8. A hectograph master sheet carrying undissolved dyestuif images andadapted for the placement of duplicate dissolved dyestuif images on aconventional copy sheet by means of heat and in the absence of spiritduplicating fluids, which comprises a paper foundation sheet havingthereon a thin solid coating which is substantiallynonpressure-transferable and which contains at least one solid solventmaterial which, in its melted state, is a solvent for hectographdyestuff, and having on said thin solid coating at least one imagecomprising hectograph composition having a higher melting temperaturethan the melting temperature of the said thin solid coating andcontaining undissolved hectograph dyestuif which is soluble in themelted solvent material of said coating.

9. A hectograph master sheet according to claim 8 in which the solventmaterial comprises at least one material selected from the groupconsisting of fatty acids, fatty alcohols, solid esters and solidethers.

10. A hectograph master sheet according to claim 8 in which thehectograph composition includes a binder material selected from thegroup consisting of wax and film-forming binder materials.

11. A hectograph master sheet carrying undissolved dyestutf images andadapted for the placement of duplicate dissolved dyestuff images on aconventional copy sheet by means of heat and in the absence of spiritduplicating fluids, which comprises an infrared radiationabsorbing paperfoundation sheet having thereon a thin solid coating which issubstantially non-pressure-transferable and which has ameltingtemperature within the range of 90 F. to 160 F. and whichcontains at least one solid solvent material which, in its melted state,is a solvent for hectograph dyestuff, and having on said thin solidcoating at least one image comprising hectograph composition which doesnot absorb infrared radiation and which has a higher melting temperaturethan the melting temperature of the said thin solid coating and containsundissolved hectograph dyestufi which is soluble in the melted solventmaterial of said coating.

12. A hectograph master sheet carrying undissolved dyestufl images andadapted for the placement of duplicate dissolved dyestuif images on aconventional copy sheet by means of heat and in the absence of spiritduplicating fluids, which comprises a paper foundation sheet havingthereon a solid coating which is substantially non-pressure-transferableand which has a Weight of between about 2 and 7 pounds per ream and amelting temperature within the range of 90 F. to 160 F. and whichcontains at least one solid solvent material which, in its melted state,is a solvent for hectograph dyestuif, and having on said solid coatingat least one image comprising hectograph composition having a highermelting temperature than the melting temperature of the said solidcoating and containing undissolved hectograph dyestuff, which issoluble. in the melted solvent material of said coating.

References Cited by the Examiner UNITED STATES PATENTS 2,163,934 6/39Collins 101-149.4 2,501,495 3/50 Carroll et a1. 101 -1495 2,862,83212/58 Shepherd 117-32 ROBERT E. PULFREY, Primary Examiner.

DAVID KLEIN, Examiner.

1. THE PROCESS FOR DUPLICATING MASTER IMAGES ONTO A SUCCESSION OF COPYSHEETS WHICH COMPRISES THE STEPS OF: (A) FORMING A MASTER SHEETS BYAPPLYING TO A PAPER FOUNDATION SHEET A THIN SOLID COATING WHICH ISSUBSTANTIALLY NON-PRESSURE-TRANSFERABLE AND WHICH COMPRISES AT LEAST ONESOLID SOLVENT MATERIAL WHICH, IN ITS MELTED STATE, IS A SOLVENT FOR AHECTOGRAPH DYESTUFF, (B) APPLYING OVER SAID SOLID COATING IMAGES WHICHCONTAIN AN UNDISSOLVED HECTOGRAPH DYSTUFF WHICH IS SOLUBLE IN THE MELTEDSOLVENT MATERIAL OF THE COATING, SAID IMAGES HAVING A MELTINGTEMPERATURE HIGHER THAN THE MELTING TEMPERATURE OF THE SAID SOLIDCOATING, AND (C) HEATING THE IMAGED MASTER SHEET TO A TEMPERATURESUFFICIENTLY HIGH TO MELT THE SOLID COATING WITHOUT MELTING THE IMAGES,AND (D) PRESSING THE HEATED MASTER SHEET AGAINST A SUCCESSION OF COPYSHEETS WHEREBY THE MELTED SOLVENT MATERIAL DISSOLVES A PORTION OF THEHECTOGRAPH DYESTUFF ONTO EACH COPY SHEET SURFACE TO STRAIN EACH COPYSHEET SURFACE PRESSED THEREAGAINST TO FORM DISSOLVED DYESTUFF IMAGES ONTHE COPY SHEETS IN AREAS CORRESPONDING TO THE IMAGED AREAS OF THE MASTERSHEET.
 8. A HECTOGRAPH MASTER SHEET CARRYING UNDISSOLVED DYESTUFF IMAGESAND ADAPTED FOR THE PLACEMENT OF DUPLICATE DISSOLVED DYSTUFF IMAGES ON ACONVENTIONAL COPY SHEET BY MEANS OF HEAT AND IN THE ABSENCE OF SPIRITDUPLICATING FLUIDS, WHICH COMPRISES A PAPER FOUNDATION SHEET HAVINGTHEREON A THIN SOLID COATING WHICH IS SUBSTANTIALLYNONPRESSURE-TRANSFERABLE AND WHICH CONTAINS AT LEAST ONE SOLID SOLVENTMATERIAL WHICH, IN ITS MELTED STATE, IS A SOLVENT FOR HECTOGRAPHDYESTUFF, AND HAVING ON SAID THID SOLID COATING AT LEAST ONE IMAGECOMPRISING HECTOGRAPH COMPOSITION HAVING A HIGHER MELTING TEMPERATURETHAN THE MELTING TEMPERATURE OF THE SAID THIN SOLID COATING ANDCONTAINING UNDISSOLVED HECTOGRAPH DYSTUFF WHICH IS SOLUBLE IS THE MELTEDSOLVENT MATERIAL OF SAID COATING.